2008 GTI Issue

I own a 2008 GTI with a TSI motor. I was on my way to work this morning and it started to make a really loud whining noise. It sounds just like a serpentine belt slipping. When I am at a rest the car can't keep a steady idle and the rpms will go up and down from 800-2500rpm. I did a quick video on my iPhone. I jst dropped it off at the dealers, but they said they might not be able to get to it until tomorrow. I was hoping the vast knowledge the vortex could help me out.